Charts in inactive viewers do not re-render when their filter fields change

[brianblakely]

Bug Report

Steps to Reproduce:

1. Go to Superstore demo: https://perspective.finos.org/block/?example=superstore
2. Switch left-hand pane tab to untitled viewer
3. Drag over untitled to be a tab in the right-hand pane
4. untitled should now be the active tab in the right-hand pane and Sales Report (By State) should be inactive
5. Right-click the left-hand pane and select "Create Global Filter"
6. Click "Central > Illinois" in the global filter
7. Note that untitled has become filtered
8. Switch right-hand pane's active tab to Sales Report (By State)
9. Note that this viewer's filter field is updated as expected

Expected Result:

The right-hand chart should reflect the filter (by showing nothing, in this case, because it doesn't support this particular filter config).

Actual Result:

Rendering is still what it was when the viewer was last active. Screenshot:

Environment:

Perspective 2.10.0